A few years back my ph pen died. I never replaced it.
Of course, in my osmo world, all the water was exactly the same and I'd been adding the exact same amount of additives to the water for a long time.
Makes me wonder if you couldn't live without one for a while. You know what you've been feeding them. They're generally not unknown strains to your experienced grower's eye. Maybe you could trust yourself a touch more and move forward with what you probably know is the right mix and just keep that experienced grower's eye focused on the new growth for any signs of issues?
Of course, in my osmo world, all the water was exactly the same and I'd been adding the exact same amount of additives to the water for a long time.
Makes me wonder if you couldn't live without one for a while. You know what you've been feeding them. They're generally not unknown strains to your experienced grower's eye. Maybe you could trust yourself a touch more and move forward with what you probably know is the right mix and just keep that experienced grower's eye focused on the new growth for any signs of issues?